'35% of Americans will have voted before polling day'

Almost a third of American voters, if not more, would have cast their votes even before the doors to polling stations open on November 6.

Early voting, a legitimate practice, allows registered voters to cast their vote within a specified period ahead of the election day.

The US state of Iowa started Thursday. And Ohio, the most keenly contested swing state where both candidates are spending most of their time and money, starts in a week.

In some states, the period may extend over 50 days, and in some just a week. It's a trend that's been growing over the years.

"I predict 35% of voters would have cast their votes before election day this time," Michael McDonald, George Mason University academic, told HT.

His book on early voting is due out in 2013.

In fact, campaigns of both the president and Mitt Romney are mobilising their voters and supporters to cast their votes early.

In 2008, the Obama campaign took early voting to heights where it turned into a potent electoral strategy. It helped because his Republican rival John McCain did nothing.

"This time, the Romney campaign is doing quite a bit itself," said McDonald.

Voters like early voting as it helps them avoid election day queues. It is a boon for candidates as well. Early voters are scratched out from the list of those to be pursued, freeing up the campaigns to focus on those still to vote.